Ecology and the Environment

Question 1

Define population

Answer 1

Species that occupies the same habitat

Question 2

Define habitat

Answer 2

The place in which an organism lives

Question 3

Define ecosystem

Answer 3

The interactions between the biotic and abiotic factors in an area

Question 4

Define biodiversity

Answer 4

The variation between organisms

Question 5

Gice 2 abiotic factors that affect animal population sizes

Answer 5

-Temperature
-Water availability

Question 6

Give 2 biotic factors that affect the population size

Answer 6

-Number of predators
-Presence of disease and pathogens

Question 7

Define community

Answer 7

Populations of different species interacting

Question 7

Give 4 biotic factors that affect communities

Answer 7

-Number of predators
-Food availability
-Disease
-Human activity

Question 8

What is a producer?

Answer 8

An organism that makes its own food

Question 9

What is a primary consumer?

Answer 9

An organism that feeds on producers

Question 10

What is a secondary consumer?

Answer 10

An organism that feeds on primary consumers

Question 11

What is biomass

Answer 11

The dry mass of all the living organisms in an area

Question 12

Why is dry mass used for biomass?

Answer 12

Because the wet mass varies as de volume of water in the organism varies

Question 13

How do you calculate the efficiency of biomass transfer?

Answer 13

efficiency= energy transferred / total energy available x 100

Question 14

Why are biomass transfers not 100% efficient?

Answer 14

-egestion
-Excretion
-Respiration
-The production of inedible bones and shells

Question 15

How does the efficiency of biomass transfers affect the number of trophic levels in a biomass pyramid?

Answer 15

The less efficient the transfers, the fewer trophic levels and the fewer organisms in higher trophic levels.

Question 16

Difference between a food web and a food chain?

Answer 16

Food webs show the interactions of multiple different food chains. Food chains show one path of food dependencies

Question 17

3 molecules which are cycled through ecosystems

Answer 17

oxygen, carbon dioxide and water

Question 18

Describe how carbon dioxide is cycled through and ecosystem

Answer 18

-Carbon dioxide is fixed through photosynthesis
-Respiration releases carbon dioxide
-Decomposition and waste releases carbon dioxide
-Combustion releases carbon dioxide

Question 19

Describe how nitrogen is cycled through an ecosystem

Answer 19

-Nitrogen is fixed by lighting, the Haber process and bacteria
-Decomposers break dead matter down into ammonia
-Nitrifying bacteria convert ammonia into nitrates and nitrites
-Denitrifying bacteria release nitrogen back to the atmosphere

Question 20

What impacts can sulfur dioxide have on the environment?

Answer 20

-Formed when fossil fuels containing impurities are burnt
-Sulfur dioxide can dissolve in water to form acid rain which can erode buildings and pollute water sources

Question 21

What impacts can carbon monoxide have on the environment?

Answer 21

-It’s formed from the incomplete combustion of fossil fuels
-Binds irreversibly to haemoglobin which prevents it from carrying oxygen
-Too much exposure can cause unconsciousness and death

Question 22

Name 5 greenhouse gases

Answer 22

-Water vapour
-Carbon dioxide
-Nitrous oxide
-Methane
-CFCs

Question 23

Give 3 human activities that contribute to greenhouse gases

Answer 23

-Burning fossil fuels
-Deforestation
-Large scale livestock farming

Question 24

How do greenhouse gases lead to global warming?

Answer 24

-Greenhouse gases allow heat from the sun to enter the atmosphere
-The gases act as a blanket and trap the heat in the atmosphere

Question 25

Sate 3 negative consequences of global warming?

Answer 25

-Sea level rise caused by melting icebergs
-Disrupted farming and agriculture
-Increased spread of diseases in warmer climates

Question 26

Describe how sewage in waterways can affect aquatic life

Answer 26

Microorganisms that decompose sewage will use up the oxygen in the water so that there is not enough oxygen left for respiration for other aquatic organisms

Question 27

What is eutrophication?

Answer 27

An excess of nutrients in a body of water, often due to fertilisers in the water source

Question 28

What is eutrophication bad for aquatic life?

Answer 28

It causes algal bloom which decreases oxygen supplies in the water and degrades the water quality. They can also block sunlight and the dead algae bring O2 consuming bacteria

Question 29

5 negative effects of deforestation

Answer 29

-Leaching
-Less CO2 taken out of the atmosphere from photosynthesis
-Soil erosion
-Habitat disruption
-Disruption of the carbon cycle

Question 30

What is leaching?

Answer 30

Trees usually takes up lots of nutrients. When lots of tress are cut down, these nutrients can leak out into waterways. Large quantities of nutrients in waterways can cause problems such as algal bloom.

Question 31

What is evapotranspiration?

Answer 31

Process involving tress providing lots of water to the atmosphere from soil through evaporation and transpiration

Question 32

What effect does deforestation have on evapotranspiration?

Answer 32

-Less trees means that there will be less evapotranspiration
-This means that less water will be returned to the atmosphere quickly
-This causes areas to dry up